As they travel along their path, alpha rays set into motion atomic nuclei inside the structure of the glass. During these "ballistic" events, atoms are displaced, atomic bonds broken and the structure of the glass altered. The Raman spectroscopy technique, which provides information about a medium's molecular structure, can be used to reveal the scale of such changes. The Raman spectra obtained with curium-doped glass at the start of irradiation and after a dose equivalent to 10,000 years can be compared in order to estimate the effects of the dose on the structure of the glass. The similarity of the two curves shows that the structure and basic properties of the glass remain largely unchanged.